LSU AgCenter Horticulturist
Loss of trees is a common catastrophe during hurricanes, tornadoes and other weather events. Water-saturated soils also can contribute to trees uprooting during heavy winds. In addition, ice storms, although rare, can cause structural damage.
We have had our share of winter ice, flooding and heavy winds from both hurricanes and tornadoes recently in Louisiana. As climate change continues and we experience more weather challenges, there are some things you can do in your yards to prepare.
One dilemma people face during heavy winds and saturated soils is losing mature shade trees. Unfortunately, many of those trees may have taken 20 to 30 years to reach a mature size, and now those landscapes have a large void. Many homeowners are looking to replace those gaps but don’t have the time for new trees to reach full maturity. To help get landscapes restored back to its once full look, many homeowners are looking for fast-growing trees and shrubs.
One of the tradeoffs for fast-growing trees can be weak wood. Avoid selecting trees with weak wood or structural problems that you may lose in coming storms. Some examples of fast-growing trees that have weak wood are boxelder, Bradford pear, cottonwood, Leyland cypress, pines, river birch, silver maple, tulip poplar, white poplar and water oak.
Some examples of sturdy trees that exhibit fast growth are bald cypress, Drake elm, lacebark elm, red maples, swamp tupelo, sweet bay magnolia, sycamore, live oak, nutall oak, overcup oak, pin oak, sawtooth oak and willow oak.
In cleaning up your landscape, any limbs on trees or shrubs that were bent or broken should be removed. Trees or shrubs that are leaning and without significant damage or limb loss can be straightened out.
Start by removing broken limbs and prune broken branches. Next, clean torn areas with a sharp, clean knife or ax, leaving as much bark as possible to help the wound repair process.
If trees are uprooted or leaning, straighten and stake the tree to reset and help reestablish roots. Your chances of survival are best when one third to one half of the roots are still in the soil and the remaining exposed roots are relatively undisturbed.
Pull the tree upright and fill in soil as needed. Water the tree and gently step on the soil area surrounding the trunk of the tree to help firm the soil and remove air pockets.
Next, attach three guy lines to the trunk at about two-thirds of the height of the tree. Anchor in place with stakes at an angle, placing them 12 to 15 feet from the base of the tree, and secure the lines. Be sure to wrap ropes or cables with cloth or a rubber hose.
Remove straps within a year and do not fertilize. Water to encourage new root growth. Irrigate deeply for the next one to two weeks after resetting.
Reset trees stand a 50-50 chance of surviving long-term due to root damage that will take years to reestablish. Shrubs, perennials, tropical and annuals are much more likely to recover more quickly than trees after a storm.
Plants with large leaves typically shred during high winds but will put on new growth and recover in a short time. As for other woody shrubs that were damaged during the storm, they too can recover and reach full maturity within a few years.
Flooding is another concern with hurricane weather. Roots that are in standing water for extended periods can die due to no oxygen, toxins in the soil and fungal disease. Most plant casualties from temporary flooding are vegetables and seedlings.
Signs of water stress are yellow and wilted leaves. Improve drainage by trenching to allow water to flow away from the area. Before replanting, correct and prevent flooding from happening again.
Install French drains to help water move into the soil and away from low-lying areas, or add rain gardens or swales that redirect the water to an area.
Rain gardens use moisture-loving plants that help absorb water and that will not die from standing water. You have many options, such as bald cypress, river birch, live oaks, swamp red maple, pond cypress, rushes, sweetbay magnolia, southern magnolia, ironwood, parsley hawthorn, Virginia willow, American beautyberry, yaupon holly, Florida anise, dwarf palmetto, southern wax myrtle, Louisiana iris, buttonbush, river oats, muhly grass, ironweed, golden rod, cardinal flower, cinnamon fern, Texas star, swamp mallow, swamp milkweed, rudbeckia, rain and crinum lilies.
If you have poor-draining soils due to compaction and heavy clay, you should consider adding sand to encourage drainage in addition to compost to increase the organic content of the soil. Alternatively, you can add raised beds to low-lying areas and build the soil up.
Large willow oak uprooted during Hurricane Ida. Photo by Heather Kirk-Ballard/LSU AgCenter
Snapped tree following Hurricane Ida. Photo by Kaylee Deynzer/LSU AgCenter
The Hammond Research Station has a demonstration rain garden. Photo by Ashley Edwards/LSU AgCenter
Louisiana irises make a great plant selection for a rain garden. Photo by Heather Kirk-Ballard/LSU AgCenter